On an upsetting opening day at the Rio Olympics, 4-time gold medalist and No. 5 seed Venus Williams was the big casualty falling to Belgium’s Kirsten Flipkens in the first round 4-6, 6-3, 7-6(5) in three hours, 13 minutes.

“My dream was to come to Rio, but to beat one of the greatest champions, that’s a second dream coming true,” Flipkens said after the match.

Flipkens, who was making her Olympic debut, was given little chance against the 36-year-old Williams who had just made the Wimbledon semifinals last month. And Venus, and sister Serena, have taken so much pride in the games. But the American couldn’t hold on to a break lead in the third.

“Top two, next to my win over Kvitova at Wimbledon in 2013,” Flipkens said of rating the win. “The Olympics is a tournament you play once every four years. I’ve never played the Olympics before so it was already a dream coming true for me to come here. I qualified for it, I worked a year for this, not to get medal but just to qualify and come here, but then to beat Venus Williams, one of the biggest champions in our history, on centre court, gives me goose bumps all over the place.”

America, which has dominated the sport, did get one female through early when Madison Keys rolled Danka Kovinic in straight sets. But Sloane Stephens received a similar fate by Eugenie Bouchard 6-3, 6-3 in battle of Olympic debutantes.

“I felt good out there, I was just trying to be very solid and I think I did that well,” Bouchard said. “I don’t think I gave her too many chances. I was there on every one of the return games. I was pushing her and I was close to breaking her a couple of times, so I am happy mentally. I was very focused.

Elsewhere, the No. 4 and No. 6 seeds followed Venus to the exits. Agnieszka Radwanska said the long journey to Rio didn’t help her cause in a 6-4, 7-5 loss to Saisai Zheng of China.

“I didn’t spend enough time on the practice courts as I wanted to. It took three days in a plane waiting or going to airports, is not the best preparation I dream of and I was [playing] on the first day. I could have used the extra day,” The Polish No. 1 said. “I just didn’t have enough time.”

Flipkens is a rare proponent of the modern forehand on the women’s tour: Schiavone, Stosur, McHale, Giorgi and Kuznetsova are all (relatively) smaller players who, like Flipkens, hit a very solid forehand due primarily to their modern technique. If her movement were better, she would have a lot more success, but she doesn’t defend well enough to consistently beat harder hitting players. She’s got great hands too.